1. Field of the Invention
This invention relates to traction valves and, in particular, to a traction valve used with a relay valve and capable of assuming a plurality of different configurations through assembly with multiple fluid control valves having different functions.
2. Discussion of Related Art
A conventional traction valve is used to provide traction control (differential braking) and anti-lock braking functions by providing controlled delivery of fluid to braking systems during traction control events such as when the torque commanded by the driver is too great given road surface conditions. One conventional combined traction and relay control valve is the ATR-6™ Antilock Traction Relay Valve offered for sale by Bendix Commercial Vehicle Systems LLC. The ATR-6 includes a cover assembly that is mounted onto the relay valve housing. The cover assembly includes a solenoid valve that is used to provide fluid to service brakes during a traction control event. The ATR-6 forms part of a larger fluid network of fluid controlled and electrically control valves that control the flow of fluid between fluid sources and brakes and other fluid controlled systems. Although the ATR-6 and conventional fluid networks function well for their intended purpose, the multiplicity and varied functionality of the valves in the fluid network creates a relatively complex system and challenges relating to on-vehicle packaging and a multiplicity of points at which fluid communication may be disrupted.
The inventors herein have recognized a need for a traction valve that will minimize and/or eliminate one or more of the above-identified deficiencies.